The overall objective of the Neurobiology Core is to provide the HNRC and NeuroAIDS-associated[unreadable] investigators with a set of neuropathological technical and in vivo and in vitro neurobiological resources that[unreadable] will allow for the analysis of the neurodegenerative processes associated with prolonged survival with HIV[unreadable] infection from a comprehensive and dynamic perspective. During the previous period of funding we[unreadable] developed several collaborations and provided support to over 20 funded investigators in the neuroAIDS[unreadable] field. Specifically for the renewal we will provide: 1) an array of techniques to facilitate quantitative analysis[unreadable] of neuronal injury that will facilitate studies on HIV-mediated neuropathogenesis; 2) technical assistance[unreadable] and consultation on state-of-the-art neuropathological approaches; 3) support preliminary studies that[unreadable] utilize neuropathology data; 4) mentorship for students and junior faculty in neurobiology and[unreadable] neuropathology; 5) Collaborate with the Coordinating Core to disseminate information on HIV-related[unreadable] neuropathology and 6) technical support and facilitate the establishment of international collaborations. In[unreadable] anticipation of current and future needs derived from such investigations, we will expand our studies of[unreadable] neurodegeneration to include dendritic spine analysis in luciferase yellow-filled neurons, analysis of[unreadable] neurogenesis and white matter damage, establishing HIV-infected mixed neuronal cultures, and providing[unreadable] a flexible infrastructure for novel and more sensitive 3-D reconstruction techniques between[unreadable] neuropathological and neuroimaging studies. Understanding the neuropathological basis for variants of[unreadable] neuroAIDS that have emerged in the era of HAART will help elucidate the mechanisms through which HIV[unreadable] infection leads to cognitive dysfunction and to point to new treatment strategies for neuroAIDS.[unreadable] Collaborative capacity building in resource limited settings will help research into possibly altered HIV[unreadable] neuropathogenesis related to viral and host differences in international settings.